Vibration Monitoring at Blackwall Tunnel
LandScope have been appointed to provide subsidence and vibration monitoring during demolition and piling works for a new build adjacent to the north bound section of the Blackwall Tunnel.
To meet the subsidence requirements of our client, a series of brass studs have been installed around the perimeter of the site which contains a Thames Water sewer line running circa 7 meters below ground. Where the sewer lines enter and exit the site the density of the brass studs has been increased.
Our Trimble DiNi Digital Level has been used to establish a weekly subsidence levelling regime, meeting the sub 1mm accuracy requirements of our client.
Additionally, two Vibrock V901 vibration monitors have been deployed to the site to monitor the activity during the demolition works. The vibration units trigger a real-time alarm at 5mm/s and 10mm/s PPV respectively, alerting site personnel via text message if further action is needed.
LandScope has established fixed setup locations of the vibration units to ensure the reliable and appropriate vibration readings are being measured with respect to the sewers below.
Our client is provided with a weekly report for the life-span on the project detailing the results from the subsidence monitoring along with an analysis and visualisation of the recorded data.